As Puncher suggests, this definitely seems to be a motor problem.
Too often the Beogram CD50 is diagnosed with a bad laser when the fault is actually lying somewhere else.
I agree that the faulty read CD's symptom indeed looks like a tired
laser but in more than 95% of the cases, the fault turns out to be
the spindle motor, the focus circuit or simply a matter of adjusting.
The laser block itself is an incredibly robust build, I've discarded
only one and it was because a previous repair attempt had
obviously failed badly and the focus coil was mechanically damaged.
Many repairshops reject repairs to the CD50 simply because it's
either too complicated, too time consuming, parts are no longer available or they don't have the necessary tools, test CD's, instruments, documentation etc. and that really is a shame.
Not all people see the value of these things the way we do and we
will have to face the fact that for your average repairshop, there's not
much economy in putting maybe 5 or 6 hours in a repair of a 20 year old CD player.
For the hobby repairer things look different and it can be
both educational and a challenge.
Servicing a CD 50 is nothing like your average japanese player, the number of build versions, aftermarket modifications and upgrades
is a complete jungle, not two are alike but in most cases
it can be done with a good result.
I've repaired countless of these nice players and they're worth it in my opinion.
Most send in the complete machine which allows for a complete checkup,
tray repair (another common issue) etc. but some send only the motor.
The motor is of the brushless bell-anchor type and taking it apart
is kinda tricky. The magnets inside and even the metal bell
itself will break very easily.
Martin